Metal wire fabrication



Sept. 12, 1967 O JAME$ON 3,340,712

METAL WIRE FABRICATION Filed March 1, 1965 KEITH O. JAMESON I N VEN TOR.

ATTORNEY 3,340,712 METAL WIRE FABRICATION Keith 0. Jameson, Waldohoro, Maine, assignor to Sylvania Electric Products, Inc., a corporation of Delaware Filed Mar. 1, 1965, Ser. No. 435,882 4 Claims. (CI. 72-66) ABSTRACT OF THE DISCLOSURE This invention relates to metal wire fabrication, and more particularly to forming metal wire retainers or baskets, made from refractory metals for use with vapor plating or metallizing processes.

In such processes, a metallizing chamber is utilized to reduce or decompose a coating material into a volatile compound, by heating a refractory metal basket containing the coating material. The compound is readily volatilized when heated and is transferred to an article.

The present invention is directed to the fabrication of baskets or containers for use with vaporizing processes wherein they are made from refractory metal wire stock that is formed in various shapes. One of the more practical shapes used is a comically-shaped basket having two straight legs extending outwardly therefrom. These legs are attached to electrical leads to provide connection for passing electrical current through the refractory metal baskets so that the coating material can be heated and the articles coated. The straight legs are also utilized as support members to retain the baskets in a fixed position in the vaporizing chamber.

In the prior art, the forming of a refractory metal wire basket or container is done on a bench jig, having a mandrel with a tapered end. A sufiicient length of wire, which is referred to as the initial leg, is placed and held between a retaining pin and the mandrel. Thereafter the mandrel is rotated carrying and forming the wire over the mandrel, starting at the larger diameter and diminishing to a smaller tapered tip, thereby forming a basket. Removal of the finished product from the mandrel is a very critical operation in that the initial leg has to be removed from beneath the retaining pin before it can be unwound from the mandrel. This can only be accomplished by bending the initial leg away from its intended set, to clear the leg from beneath the retaining pin. In this bending operation, the brittleness of refractory metal sometimes causes the leg to snap off, thus spoiling the complete article. Even if the leg withstands the bending operation, it will become deformed and more time is needed to restraighten the leg to its proper alignment. This forming procedure, as can be seen, is a very awkward and timeconsuming effort, which makes the finished product a more costly article than is necessary.

I have improved on the above-mentioned operation by providing a formed mandrel integral and interchangeable with a chuck of a mechanized drive. Varied mandrel core configurations can be used with this chuck arrangement. Each mandrel of my invention consists of a retractable retaining pin which can be utilized to release the finished products from the mandrel.

Therefore it is a general object of my invention to provide a retractable retaining means to facilitate removal of a form article from a mandrel.

A further object is to provide a mechanism that provides interchangeability between mandrel forms.

Other objects and features of the invention will be readily apparent from the following description and the drawing in which:

FIGURE 1 is a side elevational view of the invention.

FIGURE 2 is a detail of the retaining pin means.

FIGURE 3 is taken on the line 3-3 of FIGURE 1 showing a completed form positioned on the mandrel and FIGURE 4 is an elevational view of a finished formed article.

Referring to FIG. 1, the wire apparatus of my invention is supported on a main stanchion 10, which is secured to a bench or working table. A shaft 12, supported by the stanchion 10, has a driven gear 14 positioned at one end which is in engagement with a gear 16 of a drive shaft 18, that extends from a'motor (not shown) which will provide rotation for the shaft 12. Positioned at the other end of shaft 12 is an adjustable chuck spaced from the stanchion by a sleeve 22. The adjustable chuck 20 can be adjusted to an open position by rotating the knurled outer cylinder 24. Into this chuck a suitable mandrel 26 can be fitted and held for rotation by the shaft 12. In this particular instance I use a novel type of mandrel, the distal end of which is provided with a conicallyshaped tip 28 having recessed grooves 30 formed as a helix track. The grooves control the spacing and the general configuration of the finished products. Attached to mandrel 26 and the adjacent tip 28 is a circular collar 32 which defines a starting point for the wire to be formed. Located between the collar 32 and the chuck 20, a spool 34 having spaced apart rims 42 is keyed to the mandrel shaft 26, so that the spool 34 can be traversely moved along a limited length of shaft 26 and will also rotate with the shaft 26. Spool 34 is provided with a retaining pin 36 that extends through an enlarged bore 38 in the collar .32. This pin 38 is utilized to retain the initial leg 40 of a wire during the forming operation.

An end of an operating lever 43 is positioned between the rims 42 of spool 34, the other end of this lever terminates in an enlarged sleeve 44 that is pinned to a stubshaft 46. Stub-shaft 46 is supported for rotation by a pair of spaced-apart brackets 48, one end of shaft 46 extends beyond one bracket and has knob 50 affixed thereto. Rotation of knob 50 as seen in FIGS. 1 and 3 will move lever 43 carrying the spool 34 and pin 35 rearwardly to a position shown in phantom lines in FIG. 1.

Fabrication of a refractory metal wire container can be readily accomplished with the above-described mechanism, in that a finished form can be quickly and uniformly completed without spoilage.

To form a container with this mechanism, a length of wire considered as an initial leg 40', is placed between the pin 36 and the mandrel shaft 26; thereafter shaft 26 is rotated in a clockwise direction, as viewed in FIG. 2. This rotation of shaft 26 will form the wire 52 over the helix contour of the mandrel tip 28 until the wire 52 reaches the apex of the cone where a finishing leg 56, equal in length to leg 40 is left and directed at from that of the initial leg 40. This completes the fabrication of a container 58 as seen in FIG. 4 thereafter lever 43 is initiated by knob 50 to move spool 34 carrying pin 36 rearwardly, freeing the initial leg 40. The completed container 58 can then be removed from the mandrel tip by twisting or unscrewing in a counter-clockwise direction. It can be noted at this time that neither straight leg is misshaped by the removal operation. Repeated new containers can be fabricated by first rotating knob 50 to place the pin 36 in a position to receive a new initial leg 40. Knob 50 can be operated by other various means such as a cam or similar type mechanism.

It is apparent that modifications and changes may be made within the spirit and scope of the instant invention but it is my intention, however, only to be limited by the appended claims.

What I claim is::

1. Apparatus for fabrication of refractory metal wire basket forms comprising: an adjustable holding chuck supported for rotational movement; a mandrel shaft having a formed tip at one end and being supported for rotation by said chuck; a spool disposed on said shaft; a stop collar fixedly secured to said shaft between said spool and said formed tip; a pin projecting from said spool and normally extending through said stop colla-r whereby a leg of a segment of wire is retained on said formed tip; means for retracting said spool on said shaft; whereby said stop pin is retracted within the stop collar a distance suflicient to release the leg of a segment of wire retained on said formed tip.

2. Apparatus for fabrication of refractory metal wire basket forms comprising: a mandrel shaft having a formed tip at one end and being supported for rotation; a spool disposed on said shaft; a stop collar fixedly secured to said shaft between said spool and said formed tip; a stop pin projecting from said spool and normally extending through said stop collar whereby a leg of a segment of Wire is retained on said formed tip; means for retracting said spool on said shaft whereby said stop pin is ret-racted to release the leg of a segment of wire retained on said formed tip.

3. Apparatus for fabrication of refractory metal wire basket forms comprising: an adjustable holding chuck supported for rotational movement; a mandrel shaft having a helical formed tip at one end and being supported for rotation by said chuck; a retaining means disposed on said shaft; a stop collar fixedly secured on said shaft between said retaining means and said formed tip; a stop pin projecting from said retaining means and normally extending through said stop collar whereby a leg of a segment of wire is retained on said formed tip; means for retracting said retaining means on said shaft whereby said stop pin is retracted to release the leg of a segment of wire retained on said formed tip.

4. Apparatus for fabrication of refractory metal wire basket forms comprising: an adjustable holding chuck supported for rotational movement; a mandrel shaft having a formed tip; a helical screw thread disposed on said mandrel shaft; a spool disposed on said shaft; a stop collar fixedly secured on said shaft between said spool and said formed tip; a stop pin projecting from said spool and normally extending through said stop collar whereby an initial leg of a segment of wire is retained on said formed tip; means for retracting said spool on said shaft whereby said stop pin is retracted to release the initial leg of a segment of wire after the wire form is completed.

References Cited UNITED STATES PATENTS 11/1890 James 72-139 X 9/ 1908 Bartlett 72-399 

1. APPARATUS FOR FABRICATION OF REFRACTORY METAL WIRE BASKET FORMS COMPRISING: AN ADJUSTABLE HOLDING CHUCK SUPPORTED FOR ROTATIONAL MOVEMENT; A MANDREL SHAFT HAVING A FORMED TIP AT ONE END AND BEING SUPPORTED FOR ROTATION BY SAID CHUCK; A SPOOL DISPOSED ON SAID SHAFT; A STOP COLLAR FIXEDLY SECURED TO SAID SHAFT BETWEEN SAID SPOOL AND SAID FORMED TIP; A PIN PROJECTING FROM SAID SPOOL AND NORMALLY EXTENDING THROUGH SAID STOP COLLAR WHEREBY A LEG OF A SEGMENT OF WIRE IS RETAINED ON SAID FORMED TIP; MEANS FOR RETRACTING SAID SPOOL ON SAID SHAFT; WHEREBY SAID STOP PIN IS RETRACTED WITHIN THE STOP COLLAR A DISTANCE SUFFICIENT TO RELEASE THE LEG OF A SEGMENT OF WIRE RETAINED ON SAID FORMED TIP. 